Patterns of chemotherapy-induced toxicities and outcome in children and adolescents with metastatic rhabdomyosarcoma: A report from the Children's Oncology Group

Adolescents and young adults with rhabdomyosarcoma: A report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

INTRODUCTION

The impact of established prognostic factors on survival outcomes for childhood rhabdomyosarcoma (RMS) have not been well described in the adolescent and young adult (AYA) RMS patient population.

METHODS

This is a retrospective analysis of patients with newly diagnosed RMS enrolled between 1997 and 2016 on seven previously reported Children's Oncology Group (COG) clinical trials. Demographics, clinical features, treatment details, and outcome data were collected. Five-year event-free survival (EFS) and overall survival (OS) were estimated for patients diagnosed at age 15-39 years and those diagnosed under age 15 years using the Kaplan-Meier method. Log-rank test was used to compare prognostic factors for EFS and OS. Factors significant in the univariable analysis were included in a Cox proportional hazards regression model. Nonsignificant covariates were removed from the multiple regression model.

RESULTS

Total 2151 patients including 402 AYAs were analyzed. AYAs were more likely to present with primary tumors ≥5 cm in size, metastatic disease, alveolar histology, and have FOXO1 fusions compared to children. Five-year EFS for the AYA cohort was 44.2% versus 67% for children (p < .001), and 5-year OS was 52% for the AYA cohort versus 78% for children (p < .001). Multivariable analysis revealed tumor site, size and invasiveness, clinical group, and histology were prognostic in AYAs.

CONCLUSION

AYAs with RMS have a poorer prognosis compared to younger children due to multiple factors. Further research focused on AYAs to better understand RMS biology and improve treatments is critical to improve survival.

Multi-omics analysis of the gut microbiome and metabolites associated with the psychoneurological symptom cluster in children with cancer receiving chemotherapy

BACKGROUND

Children with cancer receiving chemotherapy commonly report a cluster of psychoneurological symptoms (PNS), including pain, fatigue, anxiety, depression, and cognitive dysfunction. The role of the gut microbiome and its functional metabolites in PNS is rarely studied among children with cancer. This study investigated the associations between the gut microbiome-metabolome pathways and PNS in children with cancer across chemotherapy as compared to healthy children.

METHODS

A case-control study was conducted. Cancer cases were recruited from Children's Healthcare of Atlanta and healthy controls were recruited via flyers. Participants reported PNS using the Pediatric Patient-Reported Outcomes Measurement Information System. Data for cases were collected pre-cycle two chemotherapy (T0) and post-chemotherapy (T1), whereas data for healthy controls were collected once. Gut microbiome and its metabolites were measured using fecal specimens. Gut microbiome profiling was performed using 16S rRNA V4 sequencing, and metabolome was performed using an untargeted liquid chromatography-mass spectrometry approach. A multi-omics network integration program analyzed microbiome-metabolome pathways of PNS.

RESULTS

Cases (n = 21) and controls (n = 14) had mean ages of 13.2 and 13.1 years. For cases at T0, PNS were significantly associated with microbial genera (e.g., Ruminococcus, Megasphaera, and Prevotella), which were linked with carnitine shuttle (p = 0.0003), fatty acid metabolism (p = 0.001) and activation (p = 0.001), and tryptophan metabolism (p = 0.008). Megasphaera, clustered with aspartate and asparagine metabolism (p = 0.034), carnitine shuttle (p = 0.002), and tryptophan (p = 0.019), was associated with PNS for cases at T1. Gut bacteria with potential probiotic functions, along with fatty acid metabolism, tryptophan, and carnitine shuttle, were more clustered in cancer cases than the control network and this linkage with PNS needs further studies.

CONCLUSIONS

Using multi-omics approaches, this study indicated specific microbiome-metabolome pathways linked with PNS in children with cancer across chemotherapy. Due to limitations such as antibiotic use in cancer cases, these findings need to be further confirmed in a larger cohort.

Soft Tissue Sarcomas in Adolescents and Young Adults

Soft tissue sarcomas (STS) represent a heterogeneous group of extraskeletal mesenchymal tumors that affect individuals throughout the entire age continuum. Despite this pervasive influence, key differences exist in the presentation of these sarcomas across varying age groups that have prevented a more uniform approach to management. Notably, rhabdomyosarcoma (RMS) is more common in children, while most nonrhabdomyosarcoma soft tissue sarcoma (NRSTS) subtypes are more prevalent in adults. Older patients with NRSTS appear to have more molecularly complex biology and often present with more advanced disease compared with children. Poorer outcome disparities are observed in older patients with RMS despite receiving similar treatment as younger patients. In this review, we highlight differences in epidemiology, biology, and management paradigms for pediatric and adult patients with STS and explore opportunities for a unified approach to enhance the care and outcomes within the AYA population.

How Do Adolescent and Young Adult Patients with Cancer Manage Their Chemotherapy-Related Symptoms at Home?

Chemotherapy can cause many distressing side effects, potentially impacting treatment completion and quality of life in adolescent and young adult (AYA) patients with cancer. To identify ways to help mitigate chemotherapy-related symptoms, we sought to elicit barriers and facilitators to managing symptoms experienced by AYAs with cancer through interviews. Qualitative thematic analysis identified three main domains: (1) managing chemotherapy symptoms (e.g., medication, home remedies), (2) anticipating and mitigating symptoms (e.g., management of symptoms at home, anticipatory guidance), and (3) knowing when to seek care (e.g., unexpected and unusual symptoms). This study elucidated that AYAs can successfully manage symptoms at home when given the proper guidance and this could be a focus of future efforts to improve outcomes in this population. The Clinical Trial Registration number is NCT04594096.

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

Shedding a Light on the Challenges of Adolescents and Young Adults with Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a typical tumour of childhood but can occur at any age. Several studies have reported that adolescent and young adult (AYA) patients with RMS have poorer survival than do younger patients. This review discusses the specific challenges in AYA patients with pediatric-type RMS, exploring possible underlying factors which may influence different outcomes. Reasons for AYA survival gap are likely multifactorial, and might be related to differences in tumor biology and intrinsic aggressiveness, or differences in clinical management (that could include patient referral patterns, time to diagnosis, enrolment into clinical trials, the adequacy and intensity of treatment), as well as patient factors (including physiology and comorbidity that may influence treatment tolerability, drug pharmacokinetics and efficacy). However, improved survival has been reported in the most recent studies for AYA patients treated on pediatric RMS protocols. Different strategies may help to further improve outcome, such as supporting trans-age academic societies and national/international collaborations; developing specific clinical trials without upper age limit; defining integrated and comprehensive approach to AYA patients, including the genomic aspects; establishing multidisciplinary tumor boards with involvement of both pediatric and adult oncologists to discuss all pediatric-type RMS patients; developing dedicated projects with specific treatment recommendations and registry/database.

Treatment-related toxicities associated with hospitalization in children, adolescents, and young adults with acute lymphoblastic leukemia: population level analysis

Treatment-related toxicities (TRTs) are a potential cause of survival disparities in patients with acute lymphoblastic leukemia (ALL). We aimed to identify the most frequent TRTs associated with hospitalizations at a population level in children, adolescents and young adults (AYAs). We used the California Cancer Registry linked to a statewide hospital discharge database to identify children and AYAs with TRTs within 3 years of diagnosis. We assessed the frequency of TRTs, length of stay (LOS), admission rates associated with TRTs and TRTs impact on survival. Febrile neutropenia, hypertension, and thrombocytopenia were the most common TRTs for both children and AYAs. AYAs had longer median LOS compared to children for most toxicities. AYAs at non-specialized cancer centers (SCCs) had higher frequency of admissions associated with TRTs compared to non-SCC. Cardiovascular, respiratory, gastrointestinal, renal, and infectious TRTs were associated with worse survival. This study demonstrates the burden of TRTs in patients with ALL.

Optimizing Rhabdomyosarcoma Treatment in Adolescents and Young Adults

Rhabdomyosarcoma (RMS) is the most common form of soft tissue sarcoma in children, but can also develop in adolescents and young adults (AYA). The mainstay of treatment is multi-agent chemotherapy, ideally with concomitant local treatment, including surgical resection and/or radiation therapy. Although most treatment decisions for RMS in AYA are based on scientific evidence accumulated through clinical studies of pediatric RMS, treatment outcomes are significantly inferior in AYA patients than in children. Factors responsible for the significantly poor outcomes in AYA are tumor biology, the physiology specific to the age group concerned, refractoriness to multimodal treatments, and various psychosocial and medical care issues. The present review aims to examine the various issues involved in the treatment and care of AYA patients with RMS, discuss possible solutions, and provide an overview of the literature on the topic with several observations from the author's own experience. Clinical trials for RMS in AYA are the best way to develop an optimal treatment. However, a well-designed clinical trial requires a great deal of time and resources, especially when targeting such a rare population. Until clinical trials are designed and implemented, and their findings duly analyzed, we must provide the best possible practice for RMS treatment in AYA patients based on our own expertise in manipulating the dosage schedules of various chemotherapeutic agents and administering local treatments in a manner appropriate for each patient. Precision medicine based on state-of-the-art cancer genomics will also form an integral part of this personalized approach. In the current situation, the only way to realize such a holistic treatment approach is to integrate new developments and findings, such as gene-based diagnostics and treatments, with older, fundamental evidence that can be selectively applied to individual cases.

Treatment at Specialized Cancer Centers Is Associated with Improved Survival in Adolescent and Young Adults with Soft Tissue Sarcoma

Background: Soft tissue sarcomas (STS) are a heterogeneous group of tumors whose management benefits from a multidisciplinary therapeutic approach. Published data suggest that cancer treatment at a specialized cancer center (SCC) can improve survival in other cancers. Therefore, we examined the impact of the location of treatment on survival in children and adolescents and young adults (AYAs) with STS. Methods: We performed a population-based analysis of children and AYAs hospitalized within 1 year of diagnosis with first primary STS (2000-2014) using the California Cancer Registry linked with hospitalization data. Patients were categorized based on receiving all inpatient treatments at a SCC versus part/none. Multivariable Cox proportional hazards regression identified factors associated with overall and STS-specific survival by age group. Results are presented as adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Results: Of the 1,674 patients with STS, 142 were children (0-14) and 1,532 were AYAs (15-39) and 89.4% and 40.4% received all inpatient treatments at a SCC, respectively. Overall, the 5-year survival was improved for patients who received all inpatient care at a SCC (59.8% vs. those who received part/none, 50.7%). Multivariable regression analysis found that having all treatments at a SCC was associated with better overall survival (HR, 0.79, CI: 0.65-0.95) in AYAs, but not in children. Conclusions: Our findings demonstrate that treatment for STS at a SCC is associated with better survival in AYAs. Eliminating barriers to treatment of AYAs with STS at SCCs could improve survival in this population.

Retargeting of NK-92 Cells against High-Risk Rhabdomyosarcomas by Means of an ERBB2 (HER2/Neu)-Specific Chimeric Antigen Receptor

The dismal prognosis of pediatric and young adult patients with high-risk rhabdomyosarcoma (RMS) underscores the need for novel treatment options for this patient group. In previous studies, the tumor-associated surface antigen ERBB2 (HER2/neu) was identified as targetable in high-risk RMS. As a proof of concept, in this study, a novel treatment approach against RMS tumors using a genetically modified natural killer (NK)-92 cell line (NK-92/5.28.z) as an off-the-shelf ERBB2-chimeric antigen receptor (CAR)-engineered cell product was preclinically explored. In cytotoxicity assays, NK-92/5.28.z cells specifically recognized and efficiently eliminated RMS cell suspensions, tumor cell monolayers, and 3D tumor spheroids via the ERBB2-CAR even at effector-to-target ratios as low as 1:1. In contrast to unmodified parental NK-92 cells, which failed to lyse RMS cells, NK-92/5.28.z cells proliferated and became further activated through contact with ERBB2-positive tumor cells. Furthermore, high amounts of effector molecules, such as proinflammatory and antitumoral cytokines, were found in cocultures of NK-92/5.28.z cells with tumor cells. Taken together, our data suggest the enormous potential of this approach for improving the immunotherapy of treatment-resistant tumors, revealing the dual role of NK-92/5.28.z cells as CAR-targeted killers and modulators of endogenous adaptive immunity even in the inhibitory tumor microenvironment of high-risk RMS.

Adolescent and young adult neuro-oncology: a comprehensive review

Adolescent and young adult (AYA; ages 15-39) patients represent a population that experiences significant challenges in cancer care and research, exemplified by poorer clinical outcomes as well as unmet psychosocial and reproductive health needs. Despite central nervous system (CNS) tumors being one of the most common malignancies diagnosed in the age group, there is a clear paucity of AYA CNS tumor-specific publications, especially those related to the unique psychosocial and reproductive health needs of this population of patients. In this review, we examine various aspects of AYA oncological care including tumor biology, clinical outcome, clinical trials enrollment rate, site of care, unique psychosocial needs, and oncofertility. We assess the current state of these issues, highlight areas of deficiencies, and outline the steps needed to address these concerns. We emphasize the importance of comprehensive molecular testing as part of the diagnostic work-up, expansion of clinical trial availability, access to psychosocial care and oncofertility expertise, and the development of AYA-specific clinical research to define best practices and advancing care for this population.

Advances in the management of pediatric genitourinary rhabdomyosarcoma

Recent clinical trials have revealed several unanticipated complexities in the optimal management of genitourinary rhabdomyosarcoma (RMS). Improvement in outcomes for low- and intermediate-risk RMS over the past several decades led to the design of clinical trials aimed at reducing acute and late toxicity from extirpative surgeries, conventional radiotherapy, and cytotoxic chemotherapy. Results from these studies are mixed and have illuminated areas where historical risk stratification strategies need refining. Although radiotherapy has now become the standard for local control for most patients with genitourinary RMS, recent studies are demonstrating that there may be opportunities to minimize radiation toxicity while maintaining acceptable failure-free survival. A reduction in cyclophosphamide exposure may benefit select low-risk RMS patients but recent results illustrate that decreasing therapy intensity for most genitourinary RMS patients will require careful consideration in future prospective trials. Finally, recent studies highlight differences in perspective between European and North American investigators regarding the optimal balance of increased local failure rates but less toxicity versus improved event-free survival at a cost of higher toxicity. This review focuses on the results from the most recent RMS clinical trials and discusses their implications for the management of pediatric genitourinary RMS.

Treatment Complications and Survival Among Children and Young Adults With Acute Lymphoblastic Leukemia

PURPOSE

We previously demonstrated lower early mortality for young adults (YAs) with acute lymphoblastic leukemia (ALL) who received induction treatment at specialized cancer centers (SCCs) versus community hospitals. The aim of this study is to determine the impact of inpatient location of treatment throughout therapy on long-term survival, complications, and cost-associations that have not yet been evaluated at the population level.

METHODS

Using the California Cancer Registry linked to a hospitalization database, we identified patients, 0-39 years of age, diagnosed with first primary ALL who received inpatient treatment between 1991 and 2014. Patients were classified as receiving all or part or none of their inpatient treatment at an SCC within 3 years of diagnosis. Inverse probability-weighted, multivariable Cox regression models estimated the associations between location of treatment and sociodemographic and clinical factors with survival. We compared 3-year inpatient costs overall and per day by age group and location of care.

RESULTS

Eighty-four percent (0-18 years; n = 4,549) of children and 36% of YAs (19-39 years; n = 683) received all treatment at SCCs. Receiving all treatment at an SCC was associated with superior leukemia-specific (hazard ratio [HR], 0.76; 95% CI, 0.67 to 0.88) and overall survival (HR, 0.87; 95% CI, 0.77 to 0.97) in children and in YAs (HR, 0.71; 95% CI, 0.61 to 0.83; HR, 0.70; 95% CI, 0.62 to 0.80) even after controlling for complications. The cost of inpatient care during the full course of therapy was higher in patients receiving all of their care at SCCs.

CONCLUSION

Our results demonstrate that inpatient treatment at an SCC throughout therapy is associated with superior survival; therefore, strong consideration should be given to referring these patients to SCCs.

The VAC regimen for adult rhabdomyosarcoma: Differences between adolescent/young adult and older patients

BACKGROUND

Compared to pediatric patients, adult rhabdomyosarcoma (RMS) patients have poor prognoses, but the differences in prognoses and treatment sensitivity between adolescent/young adult (AYA) patient and older RMS patients have not been established.

AIM

To evaluate and compare the efficacy and safety of the vincristine/dactinomycin/cyclophosphamide (VAC) regimen, that is, the standard combination chemotherapy regimen for pediatric RMS, in AYA and older patients.

METHODS

We retrospectively reviewed the clinical records of adolescent and adult RMS patients treated at our institution and patients treated with the VAC were enrolled in the analyses. The differences in the efficacy and safety of VAC between the AYA patients (15-39 years old) and older patients (≥40 years old) were compared.

RESULTS

Total of 23 patients were enrolled (14 AYA patients and nine older patients) were enrolled. With the median follow-up of 89.4 weeks (range 17.7-263.1 weeks), the median progression-free survival (PFS) and overall survival (OS) of the VAC regimen were 61.4 weeks (95% CI, 32.6-90.3) and 104.0 weeks (95% CI, 43.8-164.2), respectively, with no significant differences in the PFS or OS between the AYA and older patients. There were no differences in the response rate of the VAC between AYA (64.3%) and older (66.7%), either. Safety profiles were similar between the AYA and older groups, but exposure to antitumor drugs of the VAC tended to be lower in the older group; median number of total cycle of the VAC was 13 in AYA and 10 in older, cumulative cyclophosphamide dose was 16.8 g/m² in AYA and 12.8 g/m² in older, and number of vincristine skips was six in AYA and 12 in older, respectively.

CONCLUSION

There were no significant differences in responses to the VAC among AYA and older patients with RMS. With the appropriate dose modification, the VAC regimen could be a feasible treatment option for RMS patients >40 years old.

Genetics, epigenetics and redox homeostasis in rhabdomyosarcoma: Emerging targets and therapeutics

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma accounting for 5–8% of malignant tumours in children and adolescents. Children with high risk disease have poor prognosis. Anti-RMS therapies include surgery, radiation and combination chemotherapy. While these strategies improved survival rates, they have plateaued since 1990s as drugs that target differentiation and self-renewal of tumours cells have not been identified. Moreover, prevailing treatments are aggressive with drug resistance and metastasis causing failure of several treatment regimes. Significant advances have been made recently in understanding the genetic and epigenetic landscape in RMS. These studies have identified novel diagnostic and prognostic markers and opened new avenues for treatment. An important target identified in high throughput drug screening studies is reactive oxygen species (ROS). Indeed, many drugs in clinical trials for RMS impact tumour progression through ROS. In light of such emerging evidence, we discuss recent findings highlighting key pathways, epigenetic alterations and their impacts on ROS that form the basis of developing novel molecularly targeted therapies in RMS. Such targeted therapies in combination with conventional therapy could reduce adverse side effects in young survivors and lead to a decline in long-term morbidity.

Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and represents a high-grade neoplasm of skeletal myoblast-like cells. Decades of clinical and basic research have gradually improved our understanding of the pathophysiology of RMS and helped to optimize clinical care. The two major subtypes of RMS, originally characterized on the basis of light microscopic features, are driven by fundamentally different molecular mechanisms and pose distinct clinical challenges. Curative therapy depends on control of the primary tumour, which can arise at many distinct anatomical sites, as well as controlling disseminated disease that is known or assumed to be present in every case. Sophisticated risk stratification for children with RMS incorporates various clinical, pathological and molecular features, and that information is used to guide the application of multifaceted therapy. Such therapy has historically included cytotoxic chemotherapy as well as surgery, ionizing radiation or both. This Primer describes our current understanding of RMS epidemiology, disease susceptibility factors, disease mechanisms and elements of clinical care, including diagnostics, risk-based care of newly diagnosed and relapsed disease and the prevention and management of late effects in survivors. We also outline potential opportunities to further translate new biological insights into improved clinical outcomes.

Clinical outcomes of adolescents and young adults with advanced solid tumours participating in phase I trials

BACKGROUND

Adolescent and young adult (AYA) patients with advanced solid tumours are often considered for phase I clinical trials with novel agents. The outcome of AYAs in these trials have not been described before.

AIM

To study the outcome of AYA patients in phase I clinical trials.

METHODS

Clinical trial data of AYAs (defined as aged 15-39 years at diagnosis) treated at the Drug Development Unit, Royal Marsden Hospital, between 2002 and 2016, were analysed.

RESULTS

From a prospectively maintained database of 2631 patients treated in phase I trials, 219 AYA patients (8%) were identified. Major tumour types included gynaecological cancer (25%) and sarcoma (18%). Twenty-five (11%) had a known hereditary cancer syndrome (most commonly BRCA). Molecular characterisation of tumours (n = 45) identified mutations most commonly in TP53 (33%), PI3KCA (18%) and KRAS (9%). Therapeutic targets of trials included DNA damage repair (16%), phosphoinositide 3-kinase (PI3K) (16%) and angiogenesis (16%). Grade 3/4 toxicities were experienced in 26% of patients. Of the 214 evaluable patients, objective response rate was 12%, with clinical benefit rate at 6 months of 22%. Median overall survival (OS) was 7.5 months (95% confidence interval: 6.3-9.5), and 2-year OS was 11%. Of patients with responses, 36% were matched to phase I trials based on germline or somatic genetic aberrations.

CONCLUSION

We describe the outcome of the largest cohort of AYA patients treated in phase I trials. A subgroup of these patients demonstrates benefit, with several durable responses beyond 2 years. A sizeable proportion of AYA patients have cancer syndromes, significant family history or somatic molecular aberrancies which may influence novel therapeutic treatment options.

A comparative analysis of clinicopathological features and survival among early adolescents/young adults and children with low-grade glioma: a report from the Children's Oncology Group

BACKGROUND

For several types of cancer, biological differences and outcome disparities have been documented in adolescents/young adults (AYAs, 15-39 years old) versus children. This study compared clinicopathological features and survival between younger AYAs and children with low-grade glioma (LGG), a common brain tumor among AYAs.

METHODS

This was a secondary analysis of Children's Oncology Group legacy study CCG-9891/POG-9130, which enrolled participants 0-21 years of age with newly-diagnosed LGG treated with surgery alone. For analysis, participants were categorized as children (0-14 years old) or early AYAs (eAYAs, 15-21 years old) and compared on demographics, clinical presentation, tumor characteristics, surgical outcomes, progression-free survival (PFS) and overall survival (OS).

RESULTS

Among 468 children and 50 eAYAs, more eAYAs presented with seizures (34.0% vs. 19.2%; p = 0.015), without other significant differences in clinicopathological features. 5-year PFS rates for children and eAYA were 80.2% (95% confidence interval [95% CI], 76.1-83.7) and 83.0% (95% CI 68.8-91.1), respectively; 5-year OS rates were 97.3% (95% CI 95.2-98.5) and 95.4% (95% CI 82.7-98.8), respectively. Multivariable analysis including all participants showed presence of residual tumor to be an independent predictor of PFS (< 1.5 cm³, hazard ratio [HR] 5.93 [95% CI 3.45-10.18]) and (≥ 1.5 cm³, HR 8.38 [95% CI 4.75-14.79]) (p < 0.001), while midline-chiasmatic location (HR 9.69 [95% CI 3.05-30.75], p < 0.001) and non-pilocytic astrocytoma histology (HR 6.77 [95% CI 2.35-19.49], p < 0.001) were independent predictors of OS.

CONCLUSION

Unlike several other cancers, LGG has similar presenting features and survival for both eAYAs and children. This support continuing a unified treatment approach and enrollment of eAYAs in pediatric clinical trials for LGGs.